Answer:
8.75 × 10³
Explanation:
Multiply the coefficients and the exponential terms separately; then multiply them together
2.5 × 3.5 = 8.75.
When you multiply exponential terms, you add the exponents.
10¹⁰ × 10⁻⁷ = 10⁽¹⁰⁻⁷⁾ = 10³
The product is 8.75 × 10³.
A scientific calculator does the operation automatically. The buttons may have different labels on your calculator, but the key sequence is usually something like
2.5 Exp 10 × 8.5 Exp +/- 7 = 8.75×10⁻³
Answer:
0.214 L
Explanation:
Step 1: Write the balanced equation
This is a single displacement reaction.
Zn(s) + 2 HCl(aq) ⇒ ZnCl₂(aq) + H₂(g)
Step 2: Calculate the moles corresponding to 0.625 g of Zn
The molar mass of Zn is 65.38 g/mol.
0.625 g × 1 mol/65.38 g = 9.56 × 10⁻³ mol
Step 3: Calculate the moles of H₂ produced from 9.56 × 10⁻³ moles of Zn
The molar ratio of Zn to H₂ is 1:1. The moles of H₂ produced are 1/1 × 9.56 × 10⁻³ mol = 9.56 × 10⁻³ mol.
Step 4: Calculate the volume occupied by 9.56 × 10⁻³ moles of hydrogen
Assuming standard pressure and temperature, 1 mole of hydrogen occupies 22.4 L.
9.56 × 10⁻³ mol × 22.4 L/1 mol = 0.214 L
The answer is A.
Hope this helps,
kwrob
Answer:
9.18g
Explanation:
Step 1: Write the reduction half-reaction
Au³⁺(aq) + 3 e⁻ ⇒ Au(s)
Step 2: Calculate the mass of gold is produced when 15.0A of current are passed through a gold solution for 15.0min
We will use the following relationships:
- 1 mole of electrons has a charge of 96486 C (Faraday's constant).
- 1 mole of Au is produced when 3 moles of electrons circulate.
- The molar mass of Au is 196.97 g/mol.
The mass of gold produced is:
Answer:
K₃PO₄ + 3HCl ⇒ 3KCl + H₃PO₄
Explanation:
practice these, it gets easier. goal is to match the amount of reactants and products on both sides of the equation. cheers!
